Mean Sun (Noun)
Meaning
A theoretical sun that moves along the celestial equator at a constant speed and completes its annual course in the same amount of time the real sun takes at variable speeds.
Classification
Nouns denoting cognitive processes and contents.
Examples
- The mean sun is a theoretical concept used in astronomy to simplify calculations and provide a consistent reference point for timekeeping.
- The position of the mean sun is used to define mean solar time, which is the basis for modern civil time.
- In contrast to the real sun, the mean sun moves at a constant speed along the celestial equator, completing its annual course in 365.24219 days.
- The mean sun is often used as a reference point for calculating the positions of celestial bodies and predicting astronomical events.
- The difference between the mean sun and the real sun is known as the equation of time, which can be as much as 16 minutes over the course of a year.